ABSTRACT Preeclampsia complicates approximately 3% to 5% of pregnancies and remains a major cause of maternal and neonatal morbidity and mortality. Women who have experienced preeclampsia in one pregnancy are at high risk for preeclampsia in subsequent pregnancies with the magnitude of the risk depending on the severity and gestational age at delivery in the index pregnancy. Preeclampsia shares pathogenic similarities with adult cardiovascular diseases as well as many risk factors. Endothelial dysfunction and inflammation are fundamental for the initiation and progression of both. Prevention of preeclampsia using various supplements and medications have had limited success. In contrast, there is strong evidence that 3-hydroxy-3- methylglutaryl-coenzyme A reductase inhibitors (statins) are beneficial in primary and secondary prevention of cardiovascular mortality and other cardiovascular events. Biological plausibility, animal data, and pilot clinical trials support a similar role for pravastatin, a hydrophilic statin with a favorable safety profile, in preventing preeclampsia prevention. In addition, the current evidence from animal studies and human pregnancy exposure cohorts do not support previous teratogenicity claims of pravastatin. Therefore we propose a multicenter, double blind, placebo-controlled randomized clinical trial to determine whether prophylactic treatment with pravastatin administered early in pregnancy reduces preeclampsia in high-risk women. A total of 1,760 pregnant women at high risk for preeclampsia (due to history of preeclampsia in a prior pregnancy that required delivery before 36 0/7 weeks) will be randomized between 100/7 and 166/7 weeks to pravastatin 10 mg or similarly appearing placebo, daily at bedtime until delivery. Women and their neonates will be followed throughout pregnancy and up to six weeks postpartum to address the primary aim: evaluate whether treatment with pravastatin reduces the recurrence rate of preeclampsia; as well as the following secondary aims: (1) evaluate whether pravastatin improves maternal and neonatal outcomes; (2) assess the maternal and fetal/neonatal safety profile of pravastatin during pregnancy; and (3) determine whether pravastatin administration in pregnancy reverses the angiogenic imbalance associated with preeclampsia by reducing the concentrations of the anti-angiogenic factors soluble Fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sEng), and increasing that of placental growth factor PlGF (angiogenic).